OK, let's crack this. We're given 608 and our task is to multiply it by 42. Essentially, we'll be adding 608 to itself 42 times.
Step 1: 0 + 608 = 608
Step 2: 608 + 608 = 1216
Step 3: 1216 + 608 = 1824
Step 4: 1824 + 608 = 2432
Step 5: 2432 + 608 = 3040
Step 6: 3040 + 608 = 3648
Step 7: 3648 + 608 = 4256
Step 8: 4256 + 608 = 4864
Step 9: 4864 + 608 = 5472
Step 10: 5472 + 608 = 6080
Step 11: 6080 + 608 = 6688
Step 12: 6688 + 608 = 7296
Step 13: 7296 + 608 = 7904
Step 14: 7904 + 608 = 8512
Step 15: 8512 + 608 = 9120
Step 16: 9120 + 608 = 9728
Step 17: 9728 + 608 = 10336
Step 18: 10336 + 608 = 10944
Step 19: 10944 + 608 = 11552
Step 20: 11552 + 608 = 12160
Step 21: 12160 + 608 = 12768
Step 22: 12768 + 608 = 13376
Step 23: 13376 + 608 = 13984
Step 24: 13984 + 608 = 14592
Step 25: 14592 + 608 = 15200
Step 26: 15200 + 608 = 15808
Step 27: 15808 + 608 = 16416
Step 28: 16416 + 608 = 17024
Step 29: 17024 + 608 = 17632
Step 30: 17632 + 608 = 18240
Step 31: 18240 + 608 = 18848
Step 32: 18848 + 608 = 19456
Step 33: 19456 + 608 = 20064
Step 34: 20064 + 608 = 20672
Step 35: 20672 + 608 = 21280
Step 36: 21280 + 608 = 21888
Step 37: 21888 + 608 = 22496
Step 38: 22496 + 608 = 23104
Step 39: 23104 + 608 = 23712
Step 40: 23712 + 608 = 24320
Step 41: 24320 + 608 = 24928
Step 42: 24928 + 608 = 25536

So, 608*42 = 25536